I am looking at putting together a external HD, buy buying the enclosure and HD.

The issue I have is whether to buy a enclosure that is:
1. USB3 only (can find for $20-$40)
2. USB2 and esata (can find for $20-$40)
3. USB3 and esata (not many and much more expensive than 1 & 2....$100)

My main goal is speed.

Is USB3 really faster than esata, reviews indicate otherwise? due to overhead of the USB3
Is it worth it to get both USB3 and esata?

USB 3.0 is as fast as eSATA and depending on your usb 3.0 device can be faster....but usually isnt. ;)
It really depends on your device as eSATA is bascially the same as internally connected hdd...and usb 3.0 basically is the same as well BUT there are a couple insanly fast USB 3 flash drives & raid drives that will destroy a single esata drive and tie a eSATA raid enclosure of the same size.

USB 3.0 is also a heck of a lot easier to use, but it costs more as esata can be used with a simple adapter off an internal mobo header whereas usb 3 needs a usb 3 controller (either on the mobo or via pcie daughter card). It really depends on YOUR needs, and YOUR setup WRT which is "best".

Personally I would go USB 3 (as that is what I have done). Its just easier than eSATA and works even on USB 2 systems that dont have an esata port.

IF I am reading your post correctly you are saying the ENCLOSURE is going to cost you close to 1 bill? That is insane! Get a USB 3.0 only one. They are cheaper and go for about 50.
When it comes to USB 3 enclosures you want one that uses the ASMedia chipset and NOT the one that uses the JMicron one. The ASMedia based enclosures all have the same speed...its just the enclosure fancy extras that differentiate them (same with all the JM...as they are ALL slow). The only major reviews I have read with eSATA have a distinct advantage over usb 3 all uses JM controller based devices for their test OR they were using outdated firmware. There really isnt a dif big enough to go A is faster than B ;)

With USB 3.0 you NEED to make sure the firmware and drivers are up to date as the mfg'ers page for the various usb 3 controller adapter cards (and mobos with it built in) are almost always out of date.
Get the latest drivers & firmware here:SONY/NEC firmwares

IF you need a USB 3.0 controller...THEN go eSATA assuming you have eSATA. IF you dont have eSata or the adapters to make eSATA...spend a couple bucks for a x1 PCIe card OR a couple more for a faster x4 PCIe card (the x1s are slower than the x4 adapter cards even though they all use the same NEC controller).

IF you want more speed than what a HDD can provide you will need to go SSD route. A entry level 128GB SSD will smoke a HDD in speeds.
BUT remember its all well and fine having 200MB+ speeds BUT if the internal hdd's you are pushing and pulling data to/from are only good to 120mb....its a waste. ;)

__________________
"If you ever start taking things too seriously, just remember that we are talking monkeys on an organic spaceship flying through the universe." -JR

“if your opponent has a conscience, then follow Gandhi. But if you enemy has no conscience, like Hitler, then follow Bonhoeffer.” - Dr. MLK jr

Where you have purchased it...when you open the enclosure to put the HDD in....look at the chip on the board. It will either be JM or ASM logo on it. ;)

Once again USB 3.0 is going to be limited by the HDD you use. They used an older 7200.11 hdd. Just because you stick it in a ultra fast enclosure doesnt mean it will go any faster than if it was internally attached. ALSO back at the beginning of this year the controller was new and shiny and the firmware and drivers were NOT tweaked. Hell, I noticed a little boost recently when I upgraded the firmware from 3.0.2.1 to 3.0.2.7. ;)

What is your budget for the HDD. The newer Hitachi's and WD Blacks are fast, but like all things the bigger ones are faster than the smaller ones (on avg r/w speed anyways).
Also what is the internal drive you will be using? No sense getting a super fast (and more costly) HDD for the enclosure IF your internal HDD will be the bottleneck.

__________________
"If you ever start taking things too seriously, just remember that we are talking monkeys on an organic spaceship flying through the universe." -JR

“if your opponent has a conscience, then follow Gandhi. But if you enemy has no conscience, like Hitler, then follow Bonhoeffer.” - Dr. MLK jr

.spend a couple bucks for a x1 PCIe card OR a couple more for a faster x4 PCIe card (the x1s are slower than the x4 adapter cards even though they all use the same NEC controller).

No kidding.

Today I got playing around with a Vertex2 in a Vantec Nexstar3 USB3 enclosure, connected through a Vantec UGT-PC302 PCIe 1x USB3 card. It seemed to hit the wall at 100MB/s writes and 125MB/s reads, i.e. less than half it's usual sequential performance.

Then I tried it through a Bytecc BTU3-EC200 expresscard USB3 adapter in my Asus N10J netbook. It was even worse. It was then I noticed something amusing.

The PCIe 1x bottlenecked the Vertex2 almost identically to how the SATA1 in the Intel 945G(ICH7) chipset of the N10J bottlenecked its Intel X25-Mgen2.

Here are the Attos: first the Intel, then the Vertex:

See the similarity? Sorry. PCIe 1x may be good enough for HDDs but for SSDs it's as bad as SATA1.

Unfortunately I've run out of PCIe slots faster than 1x and my old mobo doesn't have onboard USB3. Sigh. Time for a new mobo.